1. Technical Field
The present invention relates to an intake negative pressure detecting device for an internal combustion engine which is designed to detect intake negative pressure inside an intake passageway within an intake pipe.
2. Background Art
There exists conventional intake negative pressure detecting devices for internal combustion engines.
A coventional internal combustion engine includes an intake pipe which extends from an internal combustion engine main body having a cylinder and a piston and in which an intake passageway formed in the interior thereof communicates with an intake passageway formed in the internal combustion engine main body. A fuel supply unit supplies fuel to the internal combustion engine main body. An intake negative pressure sensor for detecting the intake negative pressure in the intake passageway within the intake pipe and a control unit for controlling the supply of fuel to the internal combustion engine by the fuel supply unit based on a detection signal of the intake negative pressure sensor are also provided.
When the internal combustion engine is in operation, the intake negative pressure in the intake passageway is detected by the intake negative pressure sensor, and a detection signal of the sensor is then inputted into the control unit. Then, the fuel supply unit is controlled by the control unit, so that an amount of fuel that matches the intake negative pressure so detected is supplied to the internal combustion engine main body by the fuel supply unit.
According to the control of the fuel supply unit by the control unit, the fuel consumption of the internal combustion engine is improved, and inclusion of harmful substances contained in exhaust emissions is suppressed.
Incidentally, a detecting position of the intake negative pressure by the intake negative pressure sensor is situated upstream from the fuel supply unit and is far apart from the internal combustion engine main body.
Due to this, an error tends to be easily produced between a detected value of the intake negative pressure by the intake negative pressure sensor and a value of the intake negative pressure in the intake passageway in the internal combustion engine main body that results when the detection is carried out by the intake negative pressure sensor. As a result, there is caused a risk that an amount of fuel that matches the intake negative pressure in the intake passageway in the internal combustion engine main body is not supplied. Namely, there still remain areas needing to be improved with respect to the improvement in fuel consumption of the internal combustion engine and the prevention of emission of harmful substances.